title: A prospective analysis of ¹⁸F-FDG PET/CT in patients with uveal melanoma: comparison between metabolic rate of glucose (MRglu) and standardized uptake value (SUV) and correlations with histopathological features.
abstract: OBJECTIVE
  To evaluate whether standardized uptake value (SUV) and/or metabolic rate of glucose (MRglu) are different among epithelioid, mixed, and spindle cell uveal melanomas, as well as between low and high risk melanomas; to correlate ultrasonographic data and metabolic parameters with histopathological features; and to assess the role of (18)F-FDG PET/CT for evaluating prognosis.
  
  
  METHODS
  Of 34 eligible patients prospectively enrolled with clinical suspicion of medium/large uveal melanoma, 26 (15 men, mean age 62.8 ± 11.8 years) were evaluated. All patients underwent metastatic work-up, 3-D dynamic brain and whole-body (18)F-FDG PET/CT, and surgery.
  
  
  RESULTS
  Of the 26 ocular lesions, 23 showed (18)F-FDG uptake, with a sensitivity of 88 %. MRglu was significantly higher in the epithelioid cell melanomas than in the spindle cell melanomas, as well as in high-risk lesions than in low-risk lesions (p = 0.01, p = 0.02, respectively). SUV and MRglu were correlated with histopathological features while ultrasonographic data were not.
  
  
  CONCLUSIONS
  MRglu is useful for distinguishing the different cell types in uveal melanoma, as well as high-risk from low-risk lesions, while SUV is not. MRglu provides a more accurate evaluation of glucose consumption, whereas SUV provides only an estimation. In addition, the metabolic parameters correlate with histopathological features, well also reflecting cellular behaviour in ocular malignancy. A longer follow-up is needed to assess the role of (18)F-FDG in evaluating prognosis.
authors.affiliation: Institute of Nuclear Medicine, Università Cattolica del Sacro Cuore, Largo A. Gemelli, 8, 00168, Roma, Italy, ml.calcagni@rm.unicatt.it.
authors.forename: Maria Lucia
authors.initials: ML
authors.lastname: Calcagni
authors.forename: Maria Vittoria
authors.initials: MV
authors.lastname: Mattoli
authors.forename: Maria Antonietta
authors.initials: MA
authors.lastname: Blasi
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Petrone
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Sammarco
authors.forename: Luca
authors.initials: L
authors.lastname: Indovina
authors.forename: Antonino
authors.initials: A
authors.lastname: Mulè
authors.forename: Vittoria
authors.initials: V
authors.lastname: Rufini
authors.forename: Alessandro
authors.initials: A
authors.lastname: Giordano
mesh_terms: D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D014057:Tomography, X-Ray Computed; D014604:Uveal Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005947:Glucose